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EAS 106 – Section C3 – Spring 2021 – Group 8

EAS 106 – Section C3 – Spring 2021 – Group 8

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  • Nitay Eshed | Lab 2: Lightning

    Posted by Nitay Eshed on February 10, 2021 at 3:55 pm

    Lightning seems to strike randomly, hitting the tallest object in a given area. However, in some cases a shorter object will get struck even if a taller one is nearby.

    Why do short objects near taller objects get struck by lightning, and can this be reliably predicted?

    According to https://www.weather.gov/safety/lightning-fatalities, most fatalities happen in fields, however some happen near a house, or cutting down branches of a tree. People also tend to get struck less often in cities than they do in other places such as forests and fields. Lightning seems to form arcs when it strikes tall buildings as if it is going out of its way to hit it.

    Hypothesis: Taller objects have a proportionally larger range of attraction. This is why strikes on humans occur more in forests than in cities; perhaps you have to be closer to a tree for protection than to be close to a skyscraper. This may be why the first man in the weather.gov list was struck getting out of his car. This may be why lightning makes more dramatic arcs when hitting a skyscraper but when hitting a field or tree it appears more direct.

    To test this hypothesis, we will plant a 15ft metal rod in the ground vertically and then plant one 5ft. rod a certain distance from the taller rod. This will be done in a large field, or in a lab-created lightning storm. Nothing taller than the 5ft. rod will be within a huge range. We wait for lightning to strike, and every time it hits the 15ft. rod instead of the 5ft. rod, we increase the distance between them until the shorter one is struck and mark this distance. We keep increasing the distance several more times. Then we will repeat this whole experiment several times, but we change the length of the longer rod. The next experiment may be a 20ft, 30ft, or 50ft. rod and we keep going.
    The idea is that we will keep note of the distance when the shorter rod began to get struck in each experiment if the hypothesis holds true. If we find that it is true that there is some proportional change in the attraction area of a tall object, then we can use the data from all the experiments to see if there is some kind of relationship. We may find that the distance is an absolute number, or related to the difference in height, or to the height of only one object.

    We then use the conclusion that it is, in fact, a matter of distance and as responsible scientist we will also note how to predict the distance to fully answer the question of why one object is struck near a taller one. This can be used to design safer residential areas.

3 replies
    • Kristoff Gomez (he/him/his)
      Participant
      February 10, 2021 at 4:19 pm

      Question: How does the amount of force applied to the mixture of water and cornstarch affect the consistency of the mixture?
      Hypothesis: When more force is applied to the mixture, the mixture will have the consistency of a solid. When less force is applied to the mixture the consistency will resemble that of a liquid.
      How to test this project:
      Create the mixture of water and cornstarch
      Have two objects that are different in weight ( A mashed paper ball and a pen holder)
      Drop each from the same height (ex. 1 foot)
      While observing you can analyze what happens when each of the objects come in contact with the mixture.

      According to https://www.thoughtco.com/how-oobleck-works-608231 the correct term for this mixture will be called “Oobleck”. Oobleck’s origin was derived from a Dr. Suess book, “Bartholomew and the Oobleck”. Although it may seem silly, you would not believe how much is to Oobleck. Oobleck is a “non-Newtonian” fluid. A Newtonian liquid is one that keeps up steady viscosity at any random temperature. What is viscosity? Viscosity is the property that allows liquids to flow. Therefore, when the mixture is at rest, the surface of the mixture has a consistency that relates to a liquid. In addition, if the mixture is contacted with more force, it has the consistency of a solid object. The particular reason for this circumstance is the starch grains rub against each other and lock into position. This phenomenon is called “shear thickening”. This is just how the particles in a dense suspension can resist any type of force or “shears”.

    • Nitay Eshed
      Participant
      February 16, 2021 at 11:27 pm

      A very fun topic, Kristoff. I think your hypothesis and experiment are very logical, indeed we can take advantage of Newton’s 3rd law to figure this out. The research you did seems very thorough and explains your topic well, which is important for the integrity of your analysis. I think it’s very interesting how viscosity plays into this and I wonder what practical effects we can make of this. Perhaps we can transport water as oobleck inside a water tank so that when it sloshes around it gets hard and doesn’t slosh around as much since there won’t be regular fluid motion. Then we boil off the water to remove the starch and condense the water back to a liquid.

      Very cool.
      Nitay

    • Kristoff Gomez (he/him/his)
      Participant
      February 17, 2021 at 9:51 am

      I find this topic interesting and the information that you get from this topic can be extremely helpful for the people who are in areas that lightning is common. You can also use this information to guide landscape architects to make sure a home is not struck as often and I find this idea interesting!

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